The Liquid Crystal Display (LCD) comprises a plurality of pixels arranged in array, and each pixel generally comprises sub pixels of red, green, blue, three colors. Each sub pixel is controlled by one scan line and one data line. The scan line is employed to control the on and off of the sub pixel, and the data line applies various data voltage signals to make the sub pixel show various gray scales, and thus for realizing the full color image display.
With the development of the liquid crystal display technology, the demand of the people for the LCD display screen is growing, but the requirement of the display resolution is getting higher and higher, the pursuit of the image display quality gets more and more stringent. Thus, how to promote the image display quality to improve the signal quality of each input and output signal unit, becomes a subject worthy of research and discussion.
For decreasing the wiring layout, most of the present LCDs utilize the multiplex (MUX) display driving circuit. Please refer to FIG. 1, which is a multiplex type display driving circuit according to prior art, comprising:
a plurality of pixel units P arranged in array, scan lines set corresponding to each row of pixel units P, data lines set corresponding to each column of pixel units P and multiplex modules DM set corresponding to each column of pixel units P.
Each pixel unit P comprising a red sub pixel R, a green sub pixel G and a blue sub pixel B which are aligned from left to right in order, and a first switch TFT T1 electrically coupled to the red sub pixel R, a second switch TFT T2 electrically coupled to the green sub pixel G, a third switch TFT T3 electrically coupled to the blue sub pixel B; each multiplex module DM comprising a first control TFT T10, a second control TFT T20 and a third control TFT T30 respectively set corresponding to a red sub pixel R column, a green sub pixel G column and a blue sub pixel B column.
n, m are set to be positive integers, and for the pixel unit P of a nth row, a mth column: all of a gate of the first switch TFT T1, a gate of the second switch TFT T2 and a gate of the third switch TFT T3 being electrically coupled to a nth scan line G(n) set corresponding to a nth row of pixel units P, and a source of the first switch TFT T1, a source of the second switch TFT T2 and a source of the third switch TFT T3 being electrically coupled to a drain of the first control TFT T10, a drain of the second control TFT T20 and a drain of the third control TFT T30 in a mth multiplex module DM set corresponding to a mth column of pixel units P, respectively, and a drain of the first switch TFT T10, a drain of the second switch TFT T20 and a drain of the third switch TFT T30 being electrically coupled to the red sub pixel R, the green sub pixel G and the blue sub pixel B, respectively. For the mth multiplex module DM: a gate of the first control TFT T10, a gate of the second control TFT T20 and a gate of the third control TFT T30 respectively receiving a first branch control signal MUXR, a second branch control signal MUXG and a third branch control signal MUXB, and all of a source of the first control TFT T10, a source of the second control TFT T20 and a source of the third control TFT T30 being electrically coupled to a mth data line D(m) set corresponding to the mth column of pixel units P.
With combination of FIG. 1 and FIG. 2, the working procedure of the multiplex type display driving circuit according to prior art is:
step S100, the scan signal in the nth scan line G(n) is changed from low to high, all of the first switch TFTs T1, the second switch TFTs T2 and the third switch TFTs T3 of the nth row are on, and after the duration Δt, the first branch control signal MUXR is pulled high, and then, all of the first control TFTs T10 are on, and the data signals in the respective data lines start to charge all of the red sub pixels R of the nth row via the first control TFTs 10 and the first switch TFTs T1 which are on.
step S200, after charging all of the red sub pixels R is accomplished, the first branch control signal MUXR is pulled down, and after the duration Δt, the second branch control signal MUXG is pulled high, and then, all of the second control TFTs T20 are on at the same time, and the data signals in the respective data lines start to charge all of the green sub pixels G of the nth row via the second control TFTs 20 and the second switch TFTs T2 which are on.
step S300, after charging all of the green sub pixels G is accomplished, the second branch control signal MUXG is pulled down, and after the duration Δt, the third branch control signal MUXB is pulled high, and then, all of the third control TFTs T30 are on at the same time, and the data signals in the respective data lines start to charge all of the blue sub pixels B of the nth row via the third control TFTs 30 and the third switch TFTs T3 which are on.
step S400, after charging all of the blue sub pixels B is accomplished, the third branch control signal MUXB is pulled down, and after the duration Δt, the scan signal in the nth scan line G(n) is pulled down to complete the signal charging of one row cycle.
step S500, then, the scan signal in the next scan line is changed from low to high, and the aforesaid step S100 to step S400 are repeated to complete charging the entire LCD.
In the duration that the scan signal of one row is pulled high, the present multiplex type display driving circuit respectively and successively pulls up the first branch control signal MUXR, the second branch control signal MUXG, the third branch control signal MUXB to complete the charging to the red sub pixels R, the green sub pixels G, the blue sub pixels B of one row. However, as the first branch control signal MUXR (or the second branch control signal MUXG or the third branch control signal MUXB) is pulled high, all of the red sub pixels (or the green sub pixels G or the blue sub pixels B) of the corresponding row are in the larger current charging state to result in that the liquid crystal module (LCM) instantly forms a larger current pumping to the driving integrated circuit (IC) of the liquid crystal panel to lead to the IC output. Namely, the actual input signal of the driving circuit appears the glitch shown in FIG. 3.